This invention relates to a system for detecting the particular chemical component of a test fluid, for obtaining an electrical signal for detecting the particular chemical component of the test fluid in accordance with a change in the color of a carrier, i.e., reagent effected due to the chemical reaction of a reagent impregnated or contained in the carrier on a chemical reaction test piece with a test fluid added to said carrier.
Conventionally, as shown in FIG. 1, a chemical reaction test piece 11 is known which has arranged on at prescribed intervals and adhered onto its elongate transparent substrate 10 a plurality of carriers 11a, 11b, 11c and 11d having coated thereon or impregnated therein different types of chemical reaction reagents. Said test piece is generally used for test of a test fluid, e.g., the urine. The usual method for testing a test fluid using said test piece comprises immersing the test piece in the test fluid or dropping the test fluid onto a reagent carrier to impregnate said test fluid in said test piece, subjecting the test fluid and reagent to a chemical reaction for a prescribed length of time, comparing the color of the reagent, i.e., reagent carrier changing in accordance with the degree of said chemical reaction with the colors of a color comparison table thereby to investigate what reaction degree said color indicates, in other words, the sequential position of said reaction degree, thus to determine the nature, for example, concentration, pH and the like of the test fluid.
Accordingly, since the usual test using the foregoing chemical reaction test piece is carried out by artificially comparing the color of a reagent carrier with that of a color comparison table, such test is troublesome, inefficient and inaccurate, and also insanitary because, for example, in the urine test, the urine is directly manually handled.